A biomarker, or biological marker, is a substance used as an indicator of a biological state. It is a characteristic that can be objectively measured and evaluated as an indicator of specific processes.

While most people use yeast to make bread or beer, researchers have been busy in Chicago, USA using yeast to fight MND. They have found that the MND gene FUS behaves similarly in yeast as it does in motor neurones. They propose that yeast may be a good model for studying MND.